As consumers become more aware of the health impact of lipid nutrition, consumption of canola oil in the U.S. has increased. However, generic canola oil has limited use in deep frying operations, an important segment of the food processing industry, due to its instability. Oil extracted from the seed of commercial canola (rapeseed) varieties contains a relatively high (8%-13%) linolenic acid content (C.sub.18:3) (ALA). Linolenic acid has been reported to oxidize faster than other fatty acids. Linoleic and linolenic acids have been suggested as precursors to undesirable odor and flavor development in foods. Generic canola oil is unstable and easily oxidized during cooking, which in turn compromises the sensory characteristics of foods cooked in such oils. It also develops unacceptable off odors and rancid flavors during storage.
Hydrogenation can be used to improve performance attributes by lowering the amount of linoleic and linolenic acids in the oil. In this process the oil increases in saturated and trans fatty acids. Bansal et al., Journal of Food Science, Vol, 47, p. 1338 (1982) described the effect of hydrogenation under selective and nonselective conditions using commercial nickel catalysts on the chemical composition of canola oil.
Research has shown that diets high in saturated fats increase low density lipoproteins, which promote the deposition of cholesterol on blood vessels. Low fat diets have long been known to be an effective means for lowering the serum-cholesterol level in humans. Solid fat products, such as shortening and margarine, contain high levels of saturated fatty acids, typically C.sub.12:0, C.sub.14:0, C.sub.16:0 and C.sub.18:0. These saturated fatty acids are necessary to maintain the desired physical and functional characteristics of the solid fat product.
A canola shortening having improved stability in its flavor and performance attributes for use in food operations is needed. In particular, a partially hydrogenated canola shortening having improved frying performance but with low saturated fatty acid content is desired. The present invention provides such a shortening.